Comparison of the rate of successful endotracheal intubation between the "sniffing" and "ramped" positions in patients with an expected difficult intubation: a prospective randomized study.

Lee JH, Jung HC, Shim JH, Lee C - Korean J Anesthesiol (2015)

Bottom Line:
Group R showed a higher rate of successful endotracheal intubation and better laryngeal view than group S (P < 0.05).The rate of successful endotracheal intubation was higher in group R than in group S at both heights of the operating table; but, it was not different within each group.Fully trained and experienced attending anesthesiologists achieved a higher rate of successful endotracheal intubation than less experienced residents in group R (P < 0.05) but not in group S.

Affiliation: Department of Anesthesiology and Pain Medicine, Wonkwang University School of Medicine, Iksan, Korea.

ABSTRACT

Background: Optimal head and neck positioning and clinical experience are important factors for successful endotracheal intubation in patients with a difficult airway. This study aimed to investigate the rate of successful endotracheal intubation between the sniffing and ramped positions in patients with an expected difficult intubation.

Methods: The study included 204 patients with an expected difficult intubation (airway difficulty score ≥ 8) based on the preoperative airway assessment. The patients were randomized into the following groups: group S was placed in the sniffing position, and group R was placed in the ramped position during direct laryngoscopy. The primary outcome was successful endotracheal intubation and the secondary measure was laryngeal view in the ramped or sniffing position when the operating table was placed at two different heights.

Results: Group R showed a higher rate of successful endotracheal intubation and better laryngeal view than group S (P < 0.05). The rate of successful endotracheal intubation was higher in group R than in group S at both heights of the operating table; but, it was not different within each group. Laryngeal view was not different between the two groups and within each group when the two heights of the operating table were used. Fully trained and experienced attending anesthesiologists achieved a higher rate of successful endotracheal intubation than less experienced residents in group R (P < 0.05) but not in group S.

Conclusions: Ramped position and clinical experience can be important factors for laryngeal view and success rate of endotracheal intubation in patients with an expected difficult intubation.

Mentions:
Preoperative airway assessment was performed with patients in the sitting position by an attending anesthesiologist working in each hospital and who was not involved in the study. The airway difficulty score included thyromental distance, modified Mallampati class, mouth opening, neck mobility, and dentition (Table 1). Using a computer-generated random number table, patients were randomly assigned into either the sniffing position (group S) or the ramped position (group R) with different heights of the operating table (umbilical or xiphoid level), which were achieved either by the less experienced residents or the fully trained and experienced attending anesthesiologists. A total of 204 patients were assessed for eligibility, and 193 patients were randomized to two groups (group S = 97, group R = 96) according to the head and neck position because 11 patients refused to participate in the study. The residents or attending anesthesiologists in each group were randomized to the umbilical (n = 96) or xiphoid level (n = 97) according to different heights of the operating table; but, two residents attempted endotracheal intubation at the xiphoid level instead of the umbilical level in 5 cases by mistake. As a result, 102 patients were intubated at the xiphoid level and 91 patients were intubated at the umbilical level in this study (Fig. 1).

Mentions:
Preoperative airway assessment was performed with patients in the sitting position by an attending anesthesiologist working in each hospital and who was not involved in the study. The airway difficulty score included thyromental distance, modified Mallampati class, mouth opening, neck mobility, and dentition (Table 1). Using a computer-generated random number table, patients were randomly assigned into either the sniffing position (group S) or the ramped position (group R) with different heights of the operating table (umbilical or xiphoid level), which were achieved either by the less experienced residents or the fully trained and experienced attending anesthesiologists. A total of 204 patients were assessed for eligibility, and 193 patients were randomized to two groups (group S = 97, group R = 96) according to the head and neck position because 11 patients refused to participate in the study. The residents or attending anesthesiologists in each group were randomized to the umbilical (n = 96) or xiphoid level (n = 97) according to different heights of the operating table; but, two residents attempted endotracheal intubation at the xiphoid level instead of the umbilical level in 5 cases by mistake. As a result, 102 patients were intubated at the xiphoid level and 91 patients were intubated at the umbilical level in this study (Fig. 1).

Bottom Line:
Group R showed a higher rate of successful endotracheal intubation and better laryngeal view than group S (P < 0.05).The rate of successful endotracheal intubation was higher in group R than in group S at both heights of the operating table; but, it was not different within each group.Fully trained and experienced attending anesthesiologists achieved a higher rate of successful endotracheal intubation than less experienced residents in group R (P < 0.05) but not in group S.

Affiliation:
Department of Anesthesiology and Pain Medicine, Wonkwang University School of Medicine, Iksan, Korea.

ABSTRACT

Background: Optimal head and neck positioning and clinical experience are important factors for successful endotracheal intubation in patients with a difficult airway. This study aimed to investigate the rate of successful endotracheal intubation between the sniffing and ramped positions in patients with an expected difficult intubation.

Methods: The study included 204 patients with an expected difficult intubation (airway difficulty score ≥ 8) based on the preoperative airway assessment. The patients were randomized into the following groups: group S was placed in the sniffing position, and group R was placed in the ramped position during direct laryngoscopy. The primary outcome was successful endotracheal intubation and the secondary measure was laryngeal view in the ramped or sniffing position when the operating table was placed at two different heights.

Results: Group R showed a higher rate of successful endotracheal intubation and better laryngeal view than group S (P < 0.05). The rate of successful endotracheal intubation was higher in group R than in group S at both heights of the operating table; but, it was not different within each group. Laryngeal view was not different between the two groups and within each group when the two heights of the operating table were used. Fully trained and experienced attending anesthesiologists achieved a higher rate of successful endotracheal intubation than less experienced residents in group R (P < 0.05) but not in group S.

Conclusions: Ramped position and clinical experience can be important factors for laryngeal view and success rate of endotracheal intubation in patients with an expected difficult intubation.